Anything new from the straight 8 hot rodders?

C

chevy6694

Member
Hi everyone, this may seem rude,like looking over shoulders or peeking under garage doors, but I was wondering what our "Staight 8 Hot Rodders" (alleycat, Chopper Johnny and others) have been up to? I'm not quite ready to tear into my 263 yet but....Anyone tried the super-/turbocharger route recently? Lately, I've been spending way too much time watching E-bay for Mustang/T-bird M90 systems , and I'm convinced it will work. With the scoop/air filter and blower on the right, piped down to the intercooler, then up the left side to a blow thru 4-barrel on a fabricated manifold.Oh yeah, the pipe to the intercooler needs an aftermarket blow-off valve...with flamethrower!! I'm actually not looking for "big" power, maybe 180hp at 4000? 310 lb/ft at 2500? If the engine passes a visual inspection,(it's supposed to be a "good running motor") I don't plan any internal mods, like to add Pertronix multiple spark ignition.If money wasn't a concern, I'd go fuel injection,but...
 
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blower mods

Well not a lot of comments on straight 8 performance lately, mostly regular maint. questions. The blower route seemed to be the biggest bang for the buck. with out complicated engine mods, just keep the pressure below 8 pounds and it shud be alright on a stock engine. press. can be bumped up with an overhaul and replacement pistons.
 
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Thanks for the reply, just thought (hoped) someone had some new R&D to report. Do you (or anyone) have a recomendation as to which year manual (or other books) have the most/best info on the 263? I know from looking at old Chevy manuals that the "first year" of a new "thing", the manual has more specific info, and often a special publication. Any thoughts? Well, I'll keep reading.
 
Well, not as much feedback as I had hoped for, but I see it's being read a little so I'll do what I do best and keep rambling. Should I ever have the money to really go all out, I would look into de-stroking the 263. How about a .125 overbore to 3 5/16,(not sure that's really possible, but it says so in that old magazine article elsewhere on this site). Then de-stroke 5/16 to 3 13/16. Displacement stays the same, the engine would definately rev faster(a big plus), with a potentialy higher redline(not so important). You still have some of the longest rods anywhere, and this (if I understand correctly) keeps our peak cylinder pressure down. It's these long rods (and low compression) that make me believe this engine is a great candidate for super charging(even stock). Now of course if I could afford this, the pistons would be hypereutectic (forged if racing only) with oil squirt cooling under the crowns.
 
Have you looked at some of the past posts with the Bonneville '50 Buick? That car had a supercharged 320 and needed custom pistons, but went 150 something MPH!!!
 
diff strokes

the 248 crank throw is 1.999 and a 263 is 2.125 I beleive the rods are the same length using the 248 rods and having the crank offset ground will give you a slight stroke, and a bore of 1/8 will bring you up to approx. 290 cu inches. and a destroke would make it around 280cu inch. [if my math is right]:D
 
Well , this is why I'm here! Yes, the Bonneville pictures are great, there's also great video of that car, but you know that! Now, just about all my str8 knowledge comes from this site, and related links or advice, but I thought the 263 was pretty much a completely different engine, am I wrong? And, oh yeah, how about that str8 rail at Bonneville?!
 
263 straight 8

The 263 had a bigger bore,and larger insert type, rod bearing [secondchancegarage.com/public/467.cfm] The stick shift engines usually had solid lifters I believe, I,m not an expert on all the differences. but the 263 was introduced later and had many improvements.
 
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OK, that's where I was misunderstanding. I thought the 320 and 248 shared the same block/head. So the 263 is more a developement of the 248?
 
Hi Guys!!! I diffinatly not gone, just have not been posting due to other unavoidable problems. However! I now have a dig. camera and I've not been idling my time away. I've been building/making some of the coolest parts for str8's that you've never seen!!! I will be posting photos of what I've done for you to consider.

A little more about the 263. It is virtually a totaly different engine than either the 248 or 320. It just happens to have a "family" look to it. Not by accident. The 263 and probably a "big brother" were on the drawing board by no later than 1937, and test runners by 39, at the latest. These engines were intended to be in Buicks by about 40-41. Replacing the 248 and 320. Harlow Curtice, Harley Earl, and Charles Chane, had a very different idea as to where Buick was going than what we got. We got the 263 mostly by accident. It was going to be GM's first true high performance engine, long befor the "world famous" rocket 88. Is it a highperfable engine? Absolutly!!! This engine has practly not a flaw in it. 250hp? Ha!! I'm getting that out of my 248 now! 350 lb torque? Cake walk!! Supercharging not involved. BUT! As the old saying goes "speed costs, how fast do you wanna go?" and, unfortunatly, its still true. We should find out where Mr. Chane is buryed and send him weekly flowers in thanks for getting this engine out to us. alleycat
 
alleycat glad to see you are back. I have recently bought a 36 Century that has been in several Great Races in the 2000's. Drove it home from Nashville to Memphis Tennesse a distance of close to 200 miles. The mileage was about 10 mpg. I've been watching E-bay for a 50-52 320 inch motor. After reading some of your post I'm now wondering if a 263 might be better. I really enjoyed you and jyrki's dicussion on the old allycat thread. Back in my foolish youth my daddy had a 50 buick special and if I could get anyone to agree to a 20mph rolling start I was hard to beat. I seem to remember about 55+mph in low gear in the old dynaflow!
 
Thanks for joining in, can't wait to see some pis! I've great respect for those who make all their power "on the motor"! WAY COOL! And if you'll hurry up and get your prototypes into production,:thumbsup: everyone will want a straight 8 in their hot rod!!!:car: Just kidding,:bana: no pressure.:D Aside from the fact that I don't posses the expertise to build such a motor, two things lead me to supercharging. First, that's what the factory did. To restore the performance to smog motors, they turbocharged. And with it's 7 to1 compression and limited breathing the 263 resembles those engines. Second, I think it'll look cool "in the breaze", between the rails of an open wheel pickup!
 
Well, actually, I was'ent planing to be "gone" for as long as it turned out to be. The plan was; since my 248 had developed 2 rather odd problems, now was a good time to really build the baby, take photos, bring back the "alleycat" thread, put the photos there, more or less keeping it all under one roof, giving you guys real proof of what can be done. And, since the nationals are going to be about 20 miles down the road fron me, show up with the coolest str8 ever. Probably won't happen now. I've been living in california for about 3 months, will most likely be here till june. I'm a long way from my machine shop. So, I'm at least that far behind. I've got a bench full of the coolest, roughed out parts, you guys are gonna love it!!
Charley, there is only 2 ways I would use a 320 engine; its what s'post to be in the car, or you got a nice one gathering dust somewhere. The inches look nice, but, if you just gotta have the inches, it is possiable to get it out of the 263. It was desighned to get bigger. So, in your case, I would absolutly be looking to get a 263, 50-52, and since you have a stick in your car, you will have to get a stick engine as the cranks are different. However, I think that a "plug" could be made up for a auto crank to convert to a stick crank, but I've not really explored that yet, I don't think its any big deal. With a rear gear change, kiss that silly 10mpg good-bye!!
Actually, chevy, I am mulling over the idea of making some short part runs, the problem is, there are 3 engines, each different, what do I make first?? I DO like the idea of using these late model superchargers that ford&gm are putting on some of their rigs. Sleeper idea fore sure. Everybody thinks "roots" when it comes to schargers, and the kits make it easy. No kits for us. Gotta do it "old school". At any rate you WILL be addressing some internal issues either sooner or later. No free lunch!! More later. Gotta go to the dentist! alleycat
 
Hi guys. I just discovered this board by accident the other day and have been busily looking thorugh the old posts. Lots of good information here.

However, I was inspired to post this first time because of some of the misconceptions about the straight-8s. The 248 and 263 are extremely similar--the 263 has a 3/32" larger bore (3-3/16 x 4-1/8 vs. 3-3/32 x 4-1/8 for the 248) and a slightly reinforced block casting. Except for the larger pistons, most parts are interchangeable--crank, rods, head, manifolds, cam, etc. The 248 and 263 are 100% interchangeable in the engine bay of cars equipped with either engine. The 263 came about primarily to make the Dynaflow cars a little more peppy--that little 248 had a hard time making 4000-pound cars move, and to saddle it with an automatic just about killed any kind of performance. Heck, the even older 233 was similar enough to the 248 that dual carb manifolds from a '41 will bolt right on.

For the gentleman considering pulling the 320 from his 1936 Century and putting in a 263, I'd call that a HUGE mistake. If your car originally had a 320 in it, as all pre-war Centurys do, there's just no way you can make a 263 run as well, and I would hardly call installing a 263 an upgrade of any sort in a big-series car. The only advantages it might have is hydraulic valve lifters and insert bearings, both of which can be retrofitted to earlier engines (though I prefer the mechanical lifters and you can have your babbitt rods machined for inserts). The 320 is physically a much larger block with a lot of room to grow, but there's not much you can do to get more cubes out of a 263. You can't exactly build a stroker motor out of one of these! :clonk:

If you're doing it to improve gas mileage alone, the money you'll spend on such a conversion will easily pay for the extra gas to feed the original engine for years and years. By keeping the original engine, you won't hurt resale value, either. Beyond the aforementioned problems of mating the engine and transmission, think of the hassles of actually mounting the thing in there--it isn't like a small block Chevy where they're all the same size. Your 320 is more than 4 inches longer than a 248/263, and the engine mounts are at the front and back of the engine. Take out 4 inches and you're going to have to somehow fabricate new mounts up front or create a way to use the 263's side-mounts. Of course, you'll have to shorten your throttle linkage and other incidentals like that. Keep the 320--it's a vastly better engine for these big cars, will maintain your car's value, and won't cost you a fortune to reengineer the car. If you really want a 263 in a 1936 Buick, buy a smaller Special and put it in there--it's a bolt-in.

Using a later 320, while possible, will look odd--in 1948, the block castings changed to move the front motor mounts to the side of the block (on your '36, they're part of the engine's front cover). Yeah, a later block will physically fit, but it'll look weird and may interfere with your exhaust system. Keep your original block, and if you're going to do a rebuild, then you can upgrade to the later engine's insert bearings (which is the only advantage to the later motors). You can also raise the compression, which is what Buick did little by little to bump the power up through the years. You will, however, note that the biggest gains in power were through carburetion and manifolding--the dual carbs in 41-42 made 165 horsepower, a number that wasn't surpassed until they put a 4-barrel on the car in '52, where it made 170 (single-carb 320s never made more than 150 horsepower). Between those two years, the 320s didn't make much more power than the one already in your '36, and it was almost all due to small bumps in the compression ratio.

The 320s have a lot more potential and can be overbored to .125" making something like 345 cubic inches. I fully expect the 320 in my '41 Century, which will have a lot of "invisible" tricks, to make 200+ horsepower and 300+ pounds of torque without a problem and to cruise like a modern car. The weight difference between the 248/263 and the 320 isn't so great (720 vs. 800 or so pounds) that the larger engine poses any real weight handicap, either.

While I'd love to de-stroke one of these engines to get the powerband a little wider for modern driving, unless you're willing to invest in a custom-made billet crankshaft, it ain't gonna happen. You can't pull stroke out any other way.

Forced induction sounds cool, though. How about EFI, too? Those long manifolds are just begging for MPFI.

Hope this helps.
 
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Welcome:wavey: ,and yes, you've cleared some things up, for me at least:thumbsup:. I don't know how/where you've acquired your straight 8 knowledge, but I do have two questions, which year manual or other references do you recommend? and what is the maximum overbore the 263 will accept? I really want to build "stage 1"(Eaton M90 T-bird SC system with intercooler blowing thru a (probably) Holley 4 barrel) without going internal, but like alleycat wrote, I "will be addressing internal issues 'sooner or later'". That's where "if money were no object" comes in. De-stroked crank, max-over hypereutectic pistons with oil squirt cooling, revised cooling system,(see the Bonneville rail in photo archive) and port EFI (have you seen/know about "mega squirt", looks very do-able)
 
Thanks for the welcome--I'm excited to have found this place. Jyrki and I have corresponded for years, and now I know how he gets some of the great info he has!

Since acquiring my '41 Century, I've practically made it a part-time job studying the pre-war Buicks. I've talked to many experienced hobbyists and restorers and read everything I can find on the subject. I've dissected my own engine and have worked with a local restorer who specializes in 1940-41 Buicks to get questions answered. My machinist builds all the engines in this restorer's vehicles (approaching 1000 engines, he says), so he's been a great wellspring of information, too. They've hot-rodded more than a few, so they've got experience I can use.

I've explored with my machinist all kinds of ideas for getting more performance out of my 320, stuff that has worked on modern engines. I built race cars, mostly Corvettes, for many years and have built many engines. My first engine build ever was the 342 inch stroker 302 in my '93 Mustang which I built before there were "drop in" kits for such a thing. I pieced mine together the old fashioned way and had a custom crank and pistons made and used Chrysler rods. So I'm very familiar with building engines. I also built FrankenRanger, a 1997 Ford Ranger pickup with a supercharged Mustang Cobra motor in it.

On my Buick 320, things I planned and later abandoned were lightening and knife-edging the crank, lightening the flywheel and having some custom steel rods made. Things I am still doing are decking the head & block to increase compression (about .125" total, which, with pistons, should give me in the neighborhood of 8.5:1), using a new cam I'm having ground, new custom pushrods, custom Wiseco pistons with a low-friction ceramic coating, complete porting & polishing of the head, Extrude-Hone in the intake and exhaust manifolds, with Jet-Hot coating on both for heat control, insert bearings, new stainless steel valves (an idea I got from Jyrki) and modern valve springs and a custom-fabricated all-stainless 2.25" single exhaust (it needs to look stock, even though stock was 2").

All of it's just simple hot-rodding and taking advantage of 65 years of technology. But there are some things you just can't work around, like the truly poor flow characteristics of the head and the ridiculous design of the dual carb intake manifold. But at least I'm going to optimize what's there and I expect it to make decent power and drive perfectly without looking out-of-the-ordinary. I'm still planning on getting my national 1st award with it before I start driving.

References? I have a '41 shop manual and some other factory technical info, but the rest is, like many of us, just experience and trial-and-error. There seem to be people on this board who know a lot more than I do, and I'm here to learn as much as anything. It's a valuable resource.

Glad to be here!
 
Misconceptions. Yes indeed. I have a thing about being deadly accurate about what I put in print. Probably comes from being an engineer. I stand behind what I say 100%. You can take it to the bank.

I am, along with building my engines, writing a book, more accuratly, a tech manual for str8's. This won't be a coffee table book. It's going to have drawings, specs, graphs, charts, tech annaliss, everything that can aid in building a Buick str8 from mild to, well, kinda out there. It's also going to show you how to do it. Don't look for it on amazon in the near future, this is turning out to be a little more involved than I originally thought. In the mean time, you could pick through what I've posted here & there and put togather a good enough "cheet sheet" to put you in the right direction...or not, its your choise. I have one or two more blurbs about compression and manifolding and possiably s'charging at a later date. alleycat
 
I think Matt made the false assumption that most of us make that the 263 is only a 3/32 overbore of the 248. But if one looks in the 1950 shop manual, the only year both 248 and 263 engines were both used its obvious that that's not the case. The crankshaft on the 248 has journal diameters increacing from 2 5/16 in the front to 2 9/16 at the flywheel end. The 248 also has 2 inch crankpin diameter. The 263 inch motor has 2 9/16 main journals in all 5 bearings front to rear. the rod journals are also different at 2 1/8 inches. The rods on the 248 are 7 5/8 center to center.The 263 rods are 7 3/8 center to center. The pistons on the 248 are 4.328 long and the 263 pistons are only 3.764 long. The piston pin is higher in the 263 piston. The crankcase is 5/8 inch shorter center of crank to the head surface on the 263. Like Alleycat said in one of his postings that's a lot of production changes for only a 3 year production run.
 
248/263 discussion

This is great, I,ve never delved into the 248/263 actual specs , just thought they were similar.Back in the 60,s i was able to get a lo mileage 263 stick shift engine from the wrecking yd and put it in my 39 spl. coupe. It ran great but needed taller rear gear to appreciate it. seems the stouter 263 would make a great candidate for a blower motor! blower will make the cubic inches a moot point.It might need eutectic, or forged pistons, hilift rockers, blowers dont need much cam, and automatic trans, turbo 350, 250,700, or a good dynaflow, I like an engine, and driveline as simple, and bullet proof as possible.
 
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